Valve spring compressors and clamping devices



April 10, 1956 E. M. ARTHUR VALVE SPRING COMPRESSORS AND CLAMPINGDEVICES 2 Sheets-Sheet 1 Filed April 5, 1952 v I flTrORNEYJH April 10,1956 E. M. ARTHUR VALVE SPRING COMPRESSORS AND CLAMPING DEVICES FiledApril 5, 1952 2 Sheets-Sheet 2 Flqz.

INVENTOI? z I J .ATTOKNEYS.

VALVE SPRING COMPRESSORS AND CLAMPING DEVICES Evan Meir-ion Arthur, WestHeath, Birmingham, England Application April 3, 1952, Serial No. 280,296

2 Claims. (Cl. 29-215) This invention relates to valve springcompressors and clamping devices and it has for its object compressingor clamping means which are foot operated. A further object iscompressing or clamping means particularly adapted for compressingoverhead valve springs. A further object is a device in which theclamping means and the force applying means are separate units connectedby a flexible force transmitting cable.

Referring to the drawings:

Figure 1 is a side elevation of a valve spring compressor constructedaccording to this invention.

Figure 2 is a section on line IIII of Figure 1.

Figure 3 is a plan view of the clamping unit.

Figure 4 is an underside view of the clamping unit.

Figure, 5 is a section on line V-V of Figure 1.

Figure 6 is a section on line VIVI of Figure 1.

According to a convenient embodiment of this invention, an overheadvalve spring compressor or a clamping device comprises a clamping headformed as an independent unit and comprises two bars 1 and 2 forcarrying gripping arms which are slidably mounted on one another bymeans of two headed screw threaded pins which pass through slots 3 inone bar and engage tapped holes 3b in the other bar. A set of tappedholes 3c are provided in order that the range within which the grippingarms move can be obtained with diiferent distances between the arms. Thebars on opposite ends have laterally projecting portions 4 and 5respectively and gripping arms are fixed thereto. One gripping arm 6 isU-shaped in cross section and the projecting portion 5 fits into thechannel and is fixed therein by screwed pins or rivets, and the outerend of this U-shaped arm is fitted with a gripping jaw member which isconveniently in the form of an adjustable set pin 7. The other arm 8 isU-shaped in cross section at the inner end for being similarly fixed tothe projecting portion 4 on the other slide bar 1 and the two side wallsof the gripping arm are extended and splayed outwardly. A gripping jawfor engaging a valve spring comprises two jaw arms 9 suitably shaped atthe outer end and each jaw arm is detachably fitted to the side walls ofthe gripping arm conveniently by sliding the inner ends into a U-shapedmember 10 conveniently pierced and pressed from the side walls of thegripping arm 8. The jaw arms are also anchored to the gripping arm bymeans of a screwed pin 11 which passes through perforations in the wallsof the arm 8 and the two arms 9 of the gripping jaw, so that the pinserves both to fix the arms 9 in position and also to adjust thedistance apart of the gripping jaw arms 9. A clip 12 is fixed to eachgripping arm and each clip carries an anchor socket 13 for the Bowdencable mechanism. The inner member of the Bowden cable is anchored in thesocket by means of a hook 14 on which a head 14a of said inner memberbears and which book can be lifted from the socket with the head 14a andremoved to allow the inner cable to be detached by passing back throughthe socket. A helical spring 15 is arranged on the inner wire cable 16between the two gripping arms and between the slide bars and the outerends of the clamping arms to normally force the gripping jaws thereonapart. An extra length of cable is provided between the arms 6 and 8 toprovide for the adjustment when bolts 3a are fixed in the holes 3c. Thecable mechanism is operated by means of a foot lever 17 which ispivotally mounted on a floor or base plate 18 which is convenientlychannel shaped in cross section and the foot lever 17 is pivotallymounted between the sides of this channel so that when depressed itenters the channel and the foot pressing the lever is thereby only at asmall height above the ground. The base plate thus has the lever 17pivoted thereto near the ground and the liability of tilting a smallbase plate 18 is reduced to a minimum. The inner member of the Bowdencable is anchored to the foot lever intermediate its ends, so that asubstantial mechanical advantage is obtained and the outer member 16a ofthe Bowden cable which is formed of close helically coiled wire isanchored to the upper end of an arm 19 pivoted on the base plate andslidably engaged through a slot in the lever 17 in order that anchoragecan adjust itself with the movement of the foot lever to automaticallykeep the inner and outer members at the anchorage in alignment andthereby avoid undue wear and friction. The outer member 16a of theoperating cable mechanism is rotatably anchored in the head of thescrewed pin 21 slidably engaged in the socket 22 on the arm 19 and theadjustable nut 23 forms an adjustable abutment for adjusting the pointof anchorage of the end of the outer member 16a. The device thusconstructed enables the valve springs of overhead valves of internalcombustion engines to be very conveniently and quickly compressed andboth hands of the operator are free. The device is readily adapted tosuit varying conditions of application, as the initial distance apart ofthe jaws can be varied according to the required distance which thegripping arms are required to span, whilst the abutment stud on one armis also adjustable. The fitting of the Bowden cable mechanism to thegripping arms is also reversible so that the outer member of the cablemechanism can be anchored to either arm according to the varyingconditions of use. The device thus constructed can have broken ordamaged parts readily replaced.

The appliance can be readily adapted for use as a clamp and thedetachable gripping jaws can be constructed according to the shape ofthe workpiece to be gripped. The device can be readily adapted forcompressing the springs of side valves of internal combustion engines.The foot lever may be fitted with a catch to hold it depressed in theclamping position and such catch may be in the form of a pivoted ratchettoothed rack bar normally spring pressed into engagement with the catchmember on the foot lever, the rack bar being released by means of alateral movement of the foot. A spring may be fitted to normallypressthe foot lever in the release direction, and for this purpose thearm 19 is pivotally mounted on an arm 25 pivotally mounted on the pin 24pivotally connecting the foot lever 17 to the base plate 18. A mousetrap spring is mounted on the pin 24 and one end bears on the arm 25whilst the other end bears on the foot plate 18.

In a modified form the gripping arms may be pivotally mounted togetherinstead of being slidably mounted to provide the opening and closingmovement.-

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent, is:

l. A valve spring compressor or clamping device comprising a clampinghead formed of two clamping arms mounted to be movable in relation toone another, a spring urging the arms apart, a Bowden force transmittingflexible cable mechanism having the inner member thereof anchored to onesaid arm and the outer member thereof anchored to the other arm to forcethe arms towards one another, an operating unit for said forcetransmitting cable comprising a base member, a foot lever pivotallymounted on the base member and to which the inner member of the forcetransmitting cable is anchored intermediate the outer foot applying endof the foot lever and the pivoted end, an arm pivotally anchored inrelation to the base member, means for anchoring the said outer memberof the force transmitting cable to said pivoted arm, guide means on saidpivoted arm for guiding the inner member of the force transmitting cableto its anchorage on the foot lever, and means for slidably engaging saidpivoted arm with the pivoted foot lever near the point of anchorage ofthe cable to such lever so that the arm is pivoted with the foot lever,whereby the inner member of the force transmitting cable and said guidemeans are maintained in alignment when the foot lever is depressed.

2. A valve spring compressor or clamping device comprising two flatplates mounted on one another face to face, two pins detachably fixed inholes in one plate, two aligned slots in the other plate in each ofwhich a said pin engages to slidably fix the plates together, a secondset of holes in the first mentioned plate in which the pins can be fixedto adjust the clamp to be effective over two different ranges, suchplates being L-shaped and arranged to form lateral projections atopposite ends of the plates,

an arm on each lateral projection to form a U-shaped clamping memberwith the arms slidably movable in relation to one another to compress avalve spring, a gripping jaw on each of said arms, an anchor clip and aforce transmitting flexible cable fixed to each arm between the innerand outer ends of the arms so that the force applied to draw the armstogether applies a turning moment opposite the turning of the pressureapplied to the gripping jaws, the anchor clips detachably receiving theforce transmitting cable to enable the position of the clamping arms tobe reversed, a helical spring on the inner member of force transmittingflexible cable extending between the arms for urging the arms apart, anda foot operated unit for actuating the force transmitting cable.

References Cited in the file of this patent UNITED STATES PATENTS1,384,472 Leahy July 12, 1921 1,620,649 Hartz Mar. 15, 1927 1,621,820Allen Mar. 22, 1927 1,783,827 Carr Dec. 2, 1930 1,792,567 Blomberg Feb.17, 1931 2,509,516 Murphy May 30, 1950 FOREIGN PATENTS 390,843 FranceAug. 10, 1908

